[PATCH 1/1] IB: sw: rdmavt: mr: use 'time_left' variable with wait_for_completion_timeout()

[PATCH 1/1] IB: sw: rdmavt: mr: use 'time_left' variable with wait_for_completion_timeout()

[Wolfram Sang]

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/infiniband/sw/rdmavt/mr.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c
index 7a9afd5231d5..689e708032fd 100644
--- a/drivers/infiniband/sw/rdmavt/mr.c
+++ b/drivers/infiniband/sw/rdmavt/mr.c
@@ -441,7 +441,7 @@ static void rvt_dereg_clean_qps(struct rvt_mregion *mr)
  */
 static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
 {
-	unsigned long timeout;
+	unsigned long time_left;
 	struct rvt_dev_info *rdi = ib_to_rvt(mr->pd->device);
 
 	if (mr->lkey) {
@@ -451,8 +451,8 @@ static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
 		synchronize_rcu();
 	}
 
-	timeout = wait_for_completion_timeout(&mr->comp, 5 * HZ);
-	if (!timeout) {
+	time_left = wait_for_completion_timeout(&mr->comp, 5 * HZ);
+	if (!time_left) {
 		rvt_pr_err(rdi,
 			   "%s timeout mr %p pd %p lkey %x refcount %ld\n",
 			   t, mr, mr->pd, mr->lkey,
-- 
2.43.0

Re: [PATCH 1/1] IB: sw: rdmavt: mr: use 'time_left' variable with wait_for_completion_timeout()

[Dennis Dalessandro]

On 5/2/24 5:05 PM, Wolfram Sang wrote:
> There is a confusing pattern in the kernel to use a variable named 'timeout' to
> store the result of wait_for_completion_timeout() causing patterns like:
> 
> 	timeout = wait_for_completion_timeout(...)
> 	if (!timeout) return -ETIMEDOUT;
> 
> with all kinds of permutations. Use 'time_left' as a variable to make the code
> self explaining.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>  drivers/infiniband/sw/rdmavt/mr.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c
> index 7a9afd5231d5..689e708032fd 100644
> --- a/drivers/infiniband/sw/rdmavt/mr.c
> +++ b/drivers/infiniband/sw/rdmavt/mr.c
> @@ -441,7 +441,7 @@ static void rvt_dereg_clean_qps(struct rvt_mregion *mr)
>   */
>  static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
>  {
> -	unsigned long timeout;
> +	unsigned long time_left;
>  	struct rvt_dev_info *rdi = ib_to_rvt(mr->pd->device);
>  
>  	if (mr->lkey) {
> @@ -451,8 +451,8 @@ static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
>  		synchronize_rcu();
>  	}
>  
> -	timeout = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> -	if (!timeout) {
> +	time_left = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> +	if (!time_left) {
>  		rvt_pr_err(rdi,
>  			   "%s timeout mr %p pd %p lkey %x refcount %ld\n",
>  			   t, mr, mr->pd, mr->lkey,

Nah. Disagree. I think the code is just fine as it is.

-Denny

Re: [PATCH 1/1] IB: sw: rdmavt: mr: use 'time_left' variable with wait_for_completion_timeout()

[Leon Romanovsky]

On Thu, May 02, 2024 at 05:37:35PM -0400, Dennis Dalessandro wrote:
> On 5/2/24 5:05 PM, Wolfram Sang wrote:
> > There is a confusing pattern in the kernel to use a variable named 'timeout' to
> > store the result of wait_for_completion_timeout() causing patterns like:
> > 
> > 	timeout = wait_for_completion_timeout(...)
> > 	if (!timeout) return -ETIMEDOUT;
> > 
> > with all kinds of permutations. Use 'time_left' as a variable to make the code
> > self explaining.
> > 
> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > ---
> >  drivers/infiniband/sw/rdmavt/mr.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c
> > index 7a9afd5231d5..689e708032fd 100644
> > --- a/drivers/infiniband/sw/rdmavt/mr.c
> > +++ b/drivers/infiniband/sw/rdmavt/mr.c
> > @@ -441,7 +441,7 @@ static void rvt_dereg_clean_qps(struct rvt_mregion *mr)
> >   */
> >  static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
> >  {
> > -	unsigned long timeout;
> > +	unsigned long time_left;
> >  	struct rvt_dev_info *rdi = ib_to_rvt(mr->pd->device);
> >  
> >  	if (mr->lkey) {
> > @@ -451,8 +451,8 @@ static int rvt_check_refs(struct rvt_mregion *mr, const char *t)
> >  		synchronize_rcu();
> >  	}
> >  
> > -	timeout = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> > -	if (!timeout) {
> > +	time_left = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> > +	if (!time_left) {
> >  		rvt_pr_err(rdi,
> >  			   "%s timeout mr %p pd %p lkey %x refcount %ld\n",
> >  			   t, mr, mr->pd, mr->lkey,
> 
> Nah. Disagree. I think the code is just fine as it is.

I agree with Dennis. Let's drop this patch.

Thanks

> 
> -Denny

Re: [PATCH 1/1] IB: sw: rdmavt: mr: use 'time_left' variable with wait_for_completion_timeout()

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 526 bytes --]


> > > -	timeout = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> > > -	if (!timeout) {
> > > +	time_left = wait_for_completion_timeout(&mr->comp, 5 * HZ);
> > > +	if (!time_left) {
> > >  		rvt_pr_err(rdi,
> > >  			   "%s timeout mr %p pd %p lkey %x refcount %ld\n",
> > >  			   t, mr, mr->pd, mr->lkey,
> > 
> > Nah. Disagree. I think the code is just fine as it is.
> 
> I agree with Dennis. Let's drop this patch.

Okay, I added your subsystem to the discard-list. Thanks for the review
nonetheless!


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